I do not know how the expression actually came about, but it means "the best". I heard it when I was a kid, from some older family members and their friends. I have never actually said it myself, I suppose I just use the real words to say what I mean.
There are a lot of phrases that the elderly generations used, where the meaning actually got lost somewhere along the way.

I'm not certain that I've ever used this phrase, but i have definitely heard of it. It basically is just a way of saying that something is the best, or that something is really cool. I'm not sure where it comes from, though. I never really considered researching it. But it is an old phrase, and I have definitely heard other people using it. I think that it's quite a cute saying, myself! ^_^